Skin wounds on the adult newt, Notophthalmus viridescens, will be used to characterize substrate influences and assess the importance of cell surface glycoproteins (GPs) glycosaminoglycans (GAGs) during epidermal cell migration. Substrate influences will be analyzed by implanting four types of test materials under the edge of rectangular skin wounds. 1) Sheets of limb muscle and associated connective tissue (hereafter called wound beds) treated with enzymes that destroy GP sugar chains or GAGS; 2) Wound beds covalently linked to a film of concanavalin A; 3) Natural biological surfaces composed of basal and suprabasal cells of an epidermal wound epithelium, the keratinized surface of the corneal epithelium, its basal lamina and its basal lamella; 4) reconstituted substrates consisting of nucleopore filters coated with various combinations of collagen (types I through V), cyanogen bromide peptides of the alpha chains of type I collagen, laminin, GAGs, fibrin, serum, and polyaminop acids with different charges. The importance of cell surface GPs and GAGs will be assessed by interfering with GP synthesis using tunicamycin and by continuously exposing migrating cells on wounded limbs to enzymes that destroy sugars. In addition to measuring migration rates in each experiment, scanning electron microscopy will be used in selected situations to characterize substrate and epidermal morphology. The major objective of these studies is to increase our understanding of how epidermal cells interact with surrounding biological macromolecules during wound closure.